All questions of Cellular Respiration for Grade 9 Exam
Which of the following is not correct about the Krebs cycle?
- a)It starts with a six-carbon compound.
- b)It occurs in mitochondria.
- c)It is also called the citric acid cycle.
- d)The intermediate compound which links glycolysis with the Krebs cycle is malic acid.
Correct answer is option 'D'. Can you explain this answer?
Which of the following is not correct about the Krebs cycle?
a)
It starts with a six-carbon compound.
b)
It occurs in mitochondria.
c)
It is also called the citric acid cycle.
d)
The intermediate compound which links glycolysis with the Krebs cycle is malic acid.
|
Om Desai answered |
- Krebs cycle is also known as the citric acid cycle because this reaction starts with the six-carbon compound which is citric acid. It occurs in the mitochondrial matrix.
- Krebs cycle is a closed-loop cycle. And each loop of the cycle generates a molecule of ATP. This cycle consists of eight steps which include redox, dehydration, hydration, and decarboxylation reactions. It is an aerobic pathway because NADH is produced and the electrons released are used up in the next cycle which uses oxygen.
- The process of the cycle starts with the condensation of acetyl- CoA with oxaloacetate.
- This reaction is controlled by the amount of ATP present.
- If the ATP level increases then the rate of the reaction decreases and vice versa. After glycolysis, the pyruvate is then converted into acetyl CoA which enters the citric acid cycle.
- The Krebs cycle is the pathway that all organisms use to generate energy. The intermediate compound that links pyruvate to the Krebs cycle is Acetyl CoA.
- So, the answer is option (B) ‘the intermediate compound which links glycolysis with the Krebs cycle is malic acid’.
The TCA cycle is named after- a)Robert Emerson
- b)Melvin Calvin
- c)Embden
- d)Hans Krebs
Correct answer is option 'D'. Can you explain this answer?
The TCA cycle is named after
a)
Robert Emerson
b)
Melvin Calvin
c)
Embden
d)
Hans Krebs
|
|
Hitakshi Tamta answered |
*Tricarboxylic acid (TCA) cycle is a series of enzyme-catalyzed chemical reactions used by all aerobic organisms to release the stored energy........ *It is a part of cellular respiration........ *It is also called as citric acid cycle or Krebs cycles which is named after it's discoverer Hans Krebs..... Thus, the correct answer is option 'D'.
Most of the enzymes of the TCA cycle are present in- a)Intermembrane space of mitochondria
- b)Mitochondrial matrix
- c)Inner membrane of mitochondria
- d)Cytoplasm
Correct answer is option 'B'. Can you explain this answer?
Most of the enzymes of the TCA cycle are present in
a)
Intermembrane space of mitochondria
b)
Mitochondrial matrix
c)
Inner membrane of mitochondria
d)
Cytoplasm
|
Anjali Iyer answered |
Mitochondrial matrix.
In the mitochondrion, the matrix is the space within the inner membrane. ... The enzymes in the matrix facilitate reactions responsible for the production of ATP, such as the citric acid cycle, oxidative phosphorylation, oxidation of pyruvate and the beta oxidation of fatty acids.
In the mitochondrion, the matrix is the space within the inner membrane. ... The enzymes in the matrix facilitate reactions responsible for the production of ATP, such as the citric acid cycle, oxidative phosphorylation, oxidation of pyruvate and the beta oxidation of fatty acids.
Mitochondria are called the powerhouses of the cell. Which of the following observations support this statement?- a)Mitochondria are found in almost all plant and animal cells.
- b)The enzymes of the Krebs cycle and the cytochromes are found in mitochondria.
- c)Mitochondria synthesise ATP.
- d)Mitochondria have a double membrane.
Correct answer is option 'C'. Can you explain this answer?
Mitochondria are called the powerhouses of the cell. Which of the following observations support this statement?
a)
Mitochondria are found in almost all plant and animal cells.
b)
The enzymes of the Krebs cycle and the cytochromes are found in mitochondria.
c)
Mitochondria synthesise ATP.
d)
Mitochondria have a double membrane.
|
Riya Banerjee answered |
Mitochondria (singular - Mitochondrion) are known as the powerhouse of the cell because they are responsible for the release of energy from food ,i.e, cellular respiration. This energy is released in the form of ATP (adenosine triphosphate), the energy currency of the cell.
While the cells release 2 ATP, mitochondria releases 34 ATP which adds up to 36 ATP. Since a major portion of the ATP is released by mitochondria, they are called the powerhouse of the cell.
Pyruvic acid, the key product of glycolysis, can have many metabolic fates. Under aerobic conditions, it forms- a)CO2
- b)CO2+ H2O
- c)Lactic acid
- d)Acetyl CoA + CO2
Correct answer is option 'D'. Can you explain this answer?
Pyruvic acid, the key product of glycolysis, can have many metabolic fates. Under aerobic conditions, it forms
a)
CO2
b)
CO2+ H2O
c)
Lactic acid
d)
Acetyl CoA + CO2
|
|
Rohit Shah answered |
Pyruvate, the product obtained through glycolysis, gets oxidised with the loss of its carboxy group as CO2, to give acetyl Co-A, under aerobic condition. This acetyl Co-A is further oxidised completely to CO2 + H2O in citric acid cycle. Other options are incorrect as Lactic acid is formed in muscles under anaerobic conditions. Ethanol and CO2 are products of anaerobic respiration in yeast cells. CO2 and H2O are final and complete reaction products released at the end of cellular respiration.
Choose the correct statement.- a)There is a complete breakdown of glucose during fermentation.
- b)Pyruvate is formed in the mitochondrial matrix.
- c)During the conversion of succinyl CoA to succinic acid, a molecule of ATP is synthesised.
- d)Oxygen is vital in respiration for the removal of hydrogen.
Correct answer is option 'D'. Can you explain this answer?
Choose the correct statement.
a)
There is a complete breakdown of glucose during fermentation.
b)
Pyruvate is formed in the mitochondrial matrix.
c)
During the conversion of succinyl CoA to succinic acid, a molecule of ATP is synthesised.
d)
Oxygen is vital in respiration for the removal of hydrogen.
|
Hansa Sharma answered |
- Oxygen sits at the end of the electron transport chain, where it accepts electrons, hydrogen and picks up protons to form water.
- Pyruvate is formed in the cytoplasm.
- During fermentation glucose is partially broken down by glycolysis.
- During the conversion of succinyl CoA to succinic acid a molecule of GTP is synthesized.
So, the correct option is 'Oxygen is vital in respiration for removal of hydrogen'.
In which of the following do the two names refer to one and the same thing?- a)Krebs cycle and Calvin cycle
- b)Citric acid cycle and Calvin cycle
- c)Tricarboxylic acid cycle and citric acid cycle
- d)Tricarboxylic acid cycle and urea cycle
Correct answer is option 'C'. Can you explain this answer?
In which of the following do the two names refer to one and the same thing?
a)
Krebs cycle and Calvin cycle
b)
Citric acid cycle and Calvin cycle
c)
Tricarboxylic acid cycle and citric acid cycle
d)
Tricarboxylic acid cycle and urea cycle
|
Akash Saini answered |
Explanation:
The correct answer is option C, which states that the tricarboxylic acid cycle and the citric acid cycle refer to the same thing. Let's understand why this is the correct answer.
Tricarboxylic Acid Cycle:
The tricarboxylic acid (TCA) cycle, also known as the citric acid cycle or Krebs cycle, is a series of chemical reactions that occur in the mitochondria of eukaryotic cells. It is an essential metabolic pathway that plays a key role in the oxidation of carbohydrates, fats, and proteins to generate energy in the form of ATP.
Citric Acid Cycle:
The citric acid cycle, as the name suggests, is named after citric acid. It is a series of chemical reactions that take place in the mitochondria of cells. The cycle starts with the condensation of acetyl-CoA and oxaloacetate to form citrate, which is then metabolized through a series of enzymatic reactions to regenerate oxaloacetate.
Tricarboxylic Acid Cycle = Citric Acid Cycle:
The tricarboxylic acid cycle and the citric acid cycle refer to the same metabolic pathway. The cycle was initially named after its intermediate product, citric acid, and later came to be known as the tricarboxylic acid cycle due to the presence of three carboxylic acid groups in the cycle.
Conclusion:
Hence, the correct answer is option C, where the tricarboxylic acid cycle and the citric acid cycle refer to the same thing. The other options, including the Krebs cycle and Calvin cycle, the citric acid cycle and Calvin cycle, and the tricarboxylic acid cycle and urea cycle, are incorrect as they refer to different metabolic pathways or processes.
The correct answer is option C, which states that the tricarboxylic acid cycle and the citric acid cycle refer to the same thing. Let's understand why this is the correct answer.
Tricarboxylic Acid Cycle:
The tricarboxylic acid (TCA) cycle, also known as the citric acid cycle or Krebs cycle, is a series of chemical reactions that occur in the mitochondria of eukaryotic cells. It is an essential metabolic pathway that plays a key role in the oxidation of carbohydrates, fats, and proteins to generate energy in the form of ATP.
Citric Acid Cycle:
The citric acid cycle, as the name suggests, is named after citric acid. It is a series of chemical reactions that take place in the mitochondria of cells. The cycle starts with the condensation of acetyl-CoA and oxaloacetate to form citrate, which is then metabolized through a series of enzymatic reactions to regenerate oxaloacetate.
Tricarboxylic Acid Cycle = Citric Acid Cycle:
The tricarboxylic acid cycle and the citric acid cycle refer to the same metabolic pathway. The cycle was initially named after its intermediate product, citric acid, and later came to be known as the tricarboxylic acid cycle due to the presence of three carboxylic acid groups in the cycle.
Conclusion:
Hence, the correct answer is option C, where the tricarboxylic acid cycle and the citric acid cycle refer to the same thing. The other options, including the Krebs cycle and Calvin cycle, the citric acid cycle and Calvin cycle, and the tricarboxylic acid cycle and urea cycle, are incorrect as they refer to different metabolic pathways or processes.
What is the total ATP gain during glycolysis from one molecule of glucose?- a)2 ATP
- b)4 ATP
- c)6 ATP
- d)8 ATP
Correct answer is option 'A'. Can you explain this answer?
a)
2 ATP
b)
4 ATP
c)
6 ATP
d)
8 ATP
|
Ambition Institute answered |
Glycolysis directly synthesizes 4 ATP molecules, but 2 ATP are used in early steps, resulting in a net gain of 2 ATP per glucose molecule.
End-product of citric acid/Krebs cycle is- a)Citric acid
- b)CO2 + H2O
- c)Lactic acid
- d)Pyruvic acid
Correct answer is option 'B'. Can you explain this answer?
End-product of citric acid/Krebs cycle is
a)
Citric acid
b)
CO2 + H2O
c)
Lactic acid
d)
Pyruvic acid
|
|
Rajeev Saxena answered |
The eight steps of the citric acid cycle are a series of redox, dehydration, hydration, and decarboxylation reactions. Each turn of the cycle forms one GTP or ATP as well as three NADH molecules and one FADH2 molecule, which will be used in further steps of cellular respiration to produce ATP for the cell.
Which of the following is the key intermediate compound linking glycolysis to the Krebs cycle?- a)ATP
- b)Malic acid
- c)Acetyl CoA
- d)NADH
Correct answer is option 'C'. Can you explain this answer?
Which of the following is the key intermediate compound linking glycolysis to the Krebs cycle?
a)
ATP
b)
Malic acid
c)
Acetyl CoA
d)
NADH
|
|
H2O answered |
Acetyl CoA is the key intermediate between the Krebs cycle of glycolysis. After glycolysis, the glucose converts to pyruvic acid which is a three-carbon molecule. It is converted into acetyl coenzyme a by oxidative decarboxylation This, Acetyl CoA enters the Krebs cycle and along with oxaloacetic acid forms the citric acid which is a 6C compound.
Which of the following is true about glycolysis?- a)It occurs in the mitochondria of all organisms.
- b)It requires oxygen for glucose breakdown.
- c)It occurs in the cytoplasm and is universal in all living organisms.
- d)It only occurs in prokaryotes.
Correct answer is option 'C'. Can you explain this answer?
a)
It occurs in the mitochondria of all organisms.
b)
It requires oxygen for glucose breakdown.
c)
It occurs in the cytoplasm and is universal in all living organisms.
d)
It only occurs in prokaryotes.
|
Stepway Academy answered |
Glycolysis is a universal pathway occurring in the cytoplasm of all living cells and does not require oxygen.
Which enzyme catalyzes the conversion of sucrose into glucose and fructose in plants?- a)Hexokinase
- b)Invertase
- c)Phosphofructokinase
- d)Lactate dehydrogenase
Correct answer is option 'B'. Can you explain this answer?
a)
Hexokinase
b)
Invertase
c)
Phosphofructokinase
d)
Lactate dehydrogenase
|
Lead Academy answered |
Sucrose is broken down into glucose and fructose by the enzyme invertase, allowing entry into glycolysis.
Match the glycolytic intermediates with the correct carbon number:
- a)a-iii, b-iv, c-ii, d-i
- b)a-i, b-ii, c-iv, d-iii
- c)a-ii, b-i, c-iii, d-iv
- d)a-iv, b-iii, c-i, d-ii
Correct answer is option 'C'. Can you explain this answer?
Match the glycolytic intermediates with the correct carbon number:
a)
a-iii, b-iv, c-ii, d-i
b)
a-i, b-ii, c-iv, d-iii
c)
a-ii, b-i, c-iii, d-iv
d)
a-iv, b-iii, c-i, d-ii
|
Top Rankers answered |
Glucose and fructose-1,6-bisphosphate are 6-carbon compounds, while pyruvic acid and glyceraldehyde-3-phosphate are 3-carbon intermediates.
Match the pathway with its characteristics Column I (Pathway) Column II (Characteristic) a. Glycolysis i. Occurs in cytoplasm; partial oxidation of glucose b. Alcoholic fermentation ii. Produces lactic acid under anaerobic conditions c. Lactic acid fermentation iii. Produces ethanol and CO2 in anaerobic organisms d. Aerobic respiration iv. Complete oxidation of glucose in mitochondria
- a)a-iii, b-ii, c-iv, d-i
- b)a-iv, b-i, c-iii, d-ii
- c)a-ii, b-iv, c-i, d-iii
- d) a-i, b-iii, c-ii, d-iv
Correct answer is option 'D'. Can you explain this answer?
Match the pathway with its characteristics
| Column I (Pathway) | Column II (Characteristic) |
|---|---|
| a. Glycolysis | i. Occurs in cytoplasm; partial oxidation of glucose |
| b. Alcoholic fermentation | ii. Produces lactic acid under anaerobic conditions |
| c. Lactic acid fermentation | iii. Produces ethanol and CO2 in anaerobic organisms |
| d. Aerobic respiration | iv. Complete oxidation of glucose in mitochondria |
a)
a-iii, b-ii, c-iv, d-i
b)
a-iv, b-i, c-iii, d-ii
c)
a-ii, b-iv, c-i, d-iii
d)
a-i, b-iii, c-ii, d-iv
|
|
Top Rankers answered |
Glycolysis occurs in cytoplasm, alcoholic fermentation produces ethanol, lactic acid fermentation produces lactic acid, and aerobic respiration occurs in mitochondria.
In one Krebs’ cycle, decarboxylation takes place at _______ steps.
- a)One
- b)Three
- c)Two
- d)Seven
Correct answer is option 'C'. Can you explain this answer?
In one Krebs’ cycle, decarboxylation takes place at _______ steps.
a)
One
b)
Three
c)
Two
d)
Seven
|
Ciel Knowledge answered |
- Two steps of decarboxylation leads to the formation of ketoglutaric acid.
- When citric acid is formed in the cycle, it then forms cis-acotinic acid and then isocitric acid.
- Isocitric acid further forms oxalosuccinic acid which finally forms ketoglutaric acid in the presence of oxalosuccinate decarboxylase enzyme.
Why can bulky plants manage gas exchange without specialized organs?- a)All cells are dead and do not need oxygen.
- b)The distance for gas diffusion is small, and cells are near the surface.
- c)Roots actively pump oxygen into stems.
- d)Xylem tissues transport oxygen directly to leaves.
Correct answer is option 'B'. Can you explain this answer?
a)
All cells are dead and do not need oxygen.
b)
The distance for gas diffusion is small, and cells are near the surface.
c)
Roots actively pump oxygen into stems.
d)
Xylem tissues transport oxygen directly to leaves.
|
|
Ambition Institute answered |
Even in large plants, living cells are near the surface, diffusion distances are small, and lenticels help in gaseous exchange.
Assertion (A): Fermentation releases less than 7% of the energy stored in glucose.
Reason (R): Fermentation involves complete oxidation of glucose.- a)Both A and R are true, and R is the correct explanation of A.
- b)Both A and R are true, but R is not the correct explanation of A.
- c)A is true, but R is false.
- d)A is false, but R is true.
Correct answer is option 'C'. Can you explain this answer?
Reason (R): Fermentation involves complete oxidation of glucose.
a)
Both A and R are true, and R is the correct explanation of A.
b)
Both A and R are true, but R is not the correct explanation of A.
c)
A is true, but R is false.
d)
A is false, but R is true.
|
|
Stepway Academy answered |
Fermentation releases very little energy because it involves incomplete oxidation of glucose, not complete oxidation.
At which step of glycolysis is NADH + H⁺ generated?- a)Conversion of glucose to glucose-6-phosphate
- b)Conversion of phosphoenolpyruvate to pyruvate
- c)Conversion of PGAL to 1,3-bisphosphoglycerate
- d)Conversion of fructose-6-phosphate to fructose-1,6-bisphosphate
Correct answer is option 'C'. Can you explain this answer?
a)
Conversion of glucose to glucose-6-phosphate
b)
Conversion of phosphoenolpyruvate to pyruvate
c)
Conversion of PGAL to 1,3-bisphosphoglycerate
d)
Conversion of fructose-6-phosphate to fructose-1,6-bisphosphate
|
|
Lead Academy answered |
NADH + H⁺ is formed when 3-phosphoglyceraldehyde (PGAL) is oxidized to 1,3-bisphosphoglycerate.
Why is oxygen availability not a problem in photosynthesizing cells?- a)Oxygen diffuses from roots to leaves.
- b)Oxygen is actively transported by xylem vessels.
- c)Oxygen is released within the cells during photosynthesis.
- d)Oxygen is stored in vacuoles for respiration.
Correct answer is option 'C'. Can you explain this answer?
a)
Oxygen diffuses from roots to leaves.
b)
Oxygen is actively transported by xylem vessels.
c)
Oxygen is released within the cells during photosynthesis.
d)
Oxygen is stored in vacuoles for respiration.
|
|
Lead Academy answered |
During photosynthesis, oxygen is a byproduct generated within the cells themselves, making oxygen availability sufficient.
Assertion (A): Glycolysis occurs in the cytoplasm of all living organisms.
Reason (R): Glycolysis is an anaerobic pathway that does not require oxygen.- a)Both A and R are true, and R is the correct explanation of A.
- b)Both A and R are true, but R is not the correct explanation of A.
- c)A is true, but R is false.
- d)A is false, but R is true.
Correct answer is option 'A'. Can you explain this answer?
Reason (R): Glycolysis is an anaerobic pathway that does not require oxygen.
a)
Both A and R are true, and R is the correct explanation of A.
b)
Both A and R are true, but R is not the correct explanation of A.
c)
A is true, but R is false.
d)
A is false, but R is true.
|
Mohit Rajpoot answered |
Glycolysis is a universal, cytoplasmic pathway that does not require oxygen, making R the correct explanation of A.
Why does fermentation yield less energy compared to aerobic respiration?- a)No ATP is synthesized during fermentation.
- b)Fermentation uses ATP to produce ethanol or lactic acid.
- c)Glucose is completely oxidized in fermentation.
- d)Fermentation involves incomplete oxidation of glucose.
Correct answer is option 'D'. Can you explain this answer?
a)
No ATP is synthesized during fermentation.
b)
Fermentation uses ATP to produce ethanol or lactic acid.
c)
Glucose is completely oxidized in fermentation.
d)
Fermentation involves incomplete oxidation of glucose.
|
EduRev NEET answered |
Fermentation involves partial oxidation of glucose, leading to much less ATP production compared to complete oxidation in aerobic respiration.
What is the role of lactate dehydrogenase in animal cells during intense exercise?- a)Converts pyruvate to ethanol
- b)Oxidizes lactic acid to pyruvate
- c)Reduces pyruvate to lactic acid
- d)Converts NADH to NADP
Correct answer is option 'C'. Can you explain this answer?
a)
Converts pyruvate to ethanol
b)
Oxidizes lactic acid to pyruvate
c)
Reduces pyruvate to lactic acid
d)
Converts NADH to NADP
|
|
Stepway Academy answered |
Lactate dehydrogenase catalyzes the reduction of pyruvate to lactic acid under anaerobic conditions, regenerating NAD⁺.
Match the following glycolytic enzymes with their functions:Options:
- a)a-iii, b-ii, c-i, d-iv
- b)a-ii, b-i, c-iv, d-iii
- c)a-iv, b-iii, c-ii, d-i
- d)a-i, b-iv, c-iii, d-ii
Correct answer is option 'A'. Can you explain this answer?
Match the following glycolytic enzymes with their functions:Options:
a)
a-iii, b-ii, c-i, d-iv
b)
a-ii, b-i, c-iv, d-iii
c)
a-iv, b-iii, c-ii, d-i
d)
a-i, b-iv, c-iii, d-ii
|
|
Stepway Academy answered |
Hexokinase phosphorylates glucose, invertase breaks sucrose, pyruvic acid decarboxylase aids ethanol formation, and lactate dehydrogenase reduces pyruvate to lactic acid.
Which of the following statements about gaseous exchange in plants is correct?- a)Plants have specialized organs like lungs for gaseous exchange.
- b)Each plant part independently manages its own gas exchange.
- c)Plants transport large volumes of gases between different parts.
- d)Woody stems have no structures for gaseous exchange.
Correct answer is option 'B'. Can you explain this answer?
a)
Plants have specialized organs like lungs for gaseous exchange.
b)
Each plant part independently manages its own gas exchange.
c)
Plants transport large volumes of gases between different parts.
d)
Woody stems have no structures for gaseous exchange.
|
|
Stepway Academy answered |
Plants lack specialized respiratory organs, and each part (roots, stems, leaves) manages its own gas exchange through structures like stomata and lenticels.
Which enzymes are responsible for alcoholic fermentation in yeast?- a)Pyruvate dehydrogenase and alcohol oxidase
- b)Pyruvic acid decarboxylase and alcohol dehydrogenase
- c)Lactate dehydrogenase and hexokinase
- d)Phosphofructokinase and ATP synthase
Correct answer is option 'B'. Can you explain this answer?
a)
Pyruvate dehydrogenase and alcohol oxidase
b)
Pyruvic acid decarboxylase and alcohol dehydrogenase
c)
Lactate dehydrogenase and hexokinase
d)
Phosphofructokinase and ATP synthase
|
|
EduRev NEET answered |
Alcoholic fermentation involves pyruvic acid decarboxylase and alcohol dehydrogenase, converting pyruvate to ethanol and CO₂.
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